crontab - maintain crontab files for individual users (ISC Cron V4.1)
crontab [-u user] file
crontab [-u user] [-l | -r | -e][-i]
Crontab is the program used to install, deinstall or list the tables
used to drive the cron(8) daemon in ISC Cron. Each user can have their
own crontab, and though these are files in /var, they are not intended
to be edited directly.
If the cron.allow file exists, then you must be listed therein in order
to be allowed to use this command. If the cron.allow file does not
exist but the cron.deny file does exist, then you must not be listed in
the cron.deny file in order to use this command. If neither of these
files exists, only the super user will be allowed to use this command.
If the -u option is given, it specifies the name of the user whose
crontab is to be tweaked. If this option is not given, crontab exam-
ines "your" crontab, i.e., the crontab of the person executing the com-
mand. Note that su(8) can confuse crontab and that if you are running
inside of su(8) you should always use the -u option for safety’s sake.
The first form of this command is used to install a new crontab from
some named file or standard input if the pseudo-filename ‘‘-’’ is
The -l option causes the current crontab to be displayed on standard
The -r option causes the current crontab to be removed.
The -e option is used to edit the current crontab using the editor
specified by the VISUAL or EDITOR environment variables. After you
exit from the editor, the modified crontab will be installed automati-
The -i option modifies the -r option to prompt the user for a ’y/Y’
response before actually removing the crontab.
The crontab command conforms to IEEE Std1003.2-1992 (‘‘POSIX’’). This
new command syntax differs from previous versions of Vixie Cron, as
well as from the classic SVR3 syntax.
A fairly informative usage message appears if you run it with a bad
Paul Vixie <email@example.com>
4th Berkeley Distribution 29 December 1993 CRONTAB(1)
Man(1) output converted with